1. Field of the Invention
The present invention relates to a liquid-jetting apparatus for jetting a liquid, and a method for producing the same.
2. Description of the Related Art
A liquid-jetting apparatus for jetting a liquid is known, comprising, for example, nozzles which jet the liquid, pressure chambers which are communicated with the nozzles, and an actuator which changes the volume of the pressure chamber, wherein the actuator is operated to apply the pressure to the liquid contained in the pressure chamber so that the liquid is jetted from the nozzle. In particular, for example, Japanese Patent Application Laid-open No. 2004-136663 describes an ink-jet head which jets the ink from nozzles. The ink-jet head has an actuator comprising a plurality of piezoelectric sheets which are provided to cover a plurality of pressure chambers, a plurality of individual electrodes which are formed on an upper layer of the piezoelectric sheet disposed at the uppermost layer and which are opposed to the plurality of pressure chambers respectively, and a common electrode which is formed on a lower layer of the piezoelectric sheet disposed at the uppermost layer. The plurality of individual electrodes, which are formed on the upper surface of the piezoelectric sheet, are electrically connected to a flexible printed circuit board (FPC) by means of solder or the like at the lands. Further, FPC is connected to a driver IC (driving unit). When the driving voltage is selectively applied to the plurality of individual electrodes from the driver IC via FPC, then the portion of the piezoelectric sheet, which is interposed between the individual electrode and the common electrode, is deformed, and thus the pressure is applied to the ink contained in the pressure chamber.
In the case of the ink-jet head described in Japanese Patent Application Laid-open No. 2004-136663, any wiring member such as FPC is required to electrically connect the plurality of individual electrodes and the driver IC. Therefore, the production cost is expensive corresponding thereto. In recent years, it has been tried to arrange a plurality of pressure chambers at a higher density in order to satisfy both of the requests for the improvement in the image quality and the miniaturization of the ink-jet head. However, if a plurality of pressure chambers are arranged at a high density, it is necessary that a plurality of individual electrodes, which are opposed to the plurality of pressure chambers respectively, should be also arranged at a high density. However, it is extremely difficult to connect, with the solder or the like, FPC and the lands of the plurality of individual electrodes which are arranged crowdedly respectively. The connecting structure tends to be complicated in order to enhance the reliability of the electric connection, and the production steps are complicated. Therefore, such an arrangement is disadvantageous in view of the production cost.